Description: The association between ultraviolet (UV) rays, formation of oxygen-free radicals, inactivation of antioxidative enzymes, and the appearance of photokeratitis and age-related cataracts have been established. Since the possible decrease in the stratosphere?s ozone layer as well as the large incidence of cataracts in the elderly population, UV-induced cataracts have public and environmental health implications. Studies are proposed to investigate the mechanisms of UV-induced corneal and lens damage, as well as those mechanisms associated with the protective effects observed with some low molecular-weight antioxidants. Specifically, the effect of UV radiation on enzymes that catalyze the removal of radical oxygen species; enzymes related to the generation of NADPH and reduced glutathione will be studied. The alteration of these enzymatic kinetics will be determined in the presence of varying concentrations of antioxidants such as vitamin C, vitamin E, and beta-carotene. In addition, the level of gene expression and the isolation of gene(s) affected by UV irradiation in lens and cornea tissues will be investigated. The results of the proposed studies are intended to lead to a better understanding of the mechanisms of prevention of UV-induced opacity of the corneas and the lens, and could potentially address future research approaches leading to the prevention or delay of cataract formation through nutritional antioxidants.